Ectopic vestigial lesions of the neck and shoulders

A series of five vestigial lesions of the shoulder and back is reported. Their derivation is discussed and in four cases a branchial rather than a bronchial origin is favoured. The fifth case is held to represent skin involvement by thyroglossal duct elements.     

Structure and assembly of bacteriophage T3 tails

Bacteriophage T3 gene products found in the virion tail structure are identified by in vitro complementation and serum blocking activity. On the basis of these measurements, a pathway for the assembly of the T3 tail is proposed. The products of genes 11 and 12 (gp11 and gp12) are assembled on the head to form the tail. The assembly of gp11 and gp12 proceeds cooperatively, so that in the absence of either protein, attachment of the other does not occur. T3 serum blocking activity is due to gp17. Gp17 is assembled onto the tail structure after attachment of gpll and gp12 onto the head. The structure and composition of purified T3 tails have been examined. Purified tails have a sixfold longitudinal axis of symmetry. When viewed along the symmetry axis, tails appear hexagonal with a hole in the center and with bent tail fibers radiating from the apices. Tail fiber proteins are controlled by gene 17. Tails isolated from osmotically shocked T3 phage contain gp11, gp12, and gp17. In addition, isolated tails also contain gp8, a minor head protein, suggesting that gp8 is located at a unique site in the T3 head where the tail attaches.     

Protein composition of the tail and contracted sheath of bacteriophage T4

The protein composition of phage T4 tails and tail precursors has been examined using acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Sheathed tails contain 18 protein species. The precursor to a sheathed tail consists of the baseplate and tail tube, but lacks an extended sheath. It has the same protein composition as the sheathed tail except that it lacks the gene 18 product (P18). This is the only protein in extended sheaths. Contracted sheaths isolated from whole phage also contain only P18. Baseplates, the precursors to unsheathed tails, have the same protein composition as unsheathed tails except that they lack P19. Thus tail tubes are composed of P19. The size of P18 is the same before and after sheath contraction. Whatever the mechanism of the irreversible contractions process is, it does not involve any detectable cleavage of P18.     

Brenner tumour of the vagina

Vaginal tumours are rare, and Brenner tumour is one of the most infrequent vaginal lesions. Brenner tumour is a transitional tumour that typically arises in the ovaries. Some cases have been reported in the broad ligament, uterus and paratesticular structures. Only five cases have been reported in the vagina. We report a sixth case and discuss the histogenesis of this tumour, as well as the differential diagnosis with the mixed tumour of the vagina.     

The murine mutation trembler-J: proof of semidominant expression by use of the linked vestigial tail marker

Trembler-J, TrJ, is a peripheral hypomyelinating murine mutant. In intercrosses (TrJ/ + X TrJ/ +) there are severely affected (behaviorally and pathologically), mildly affected, and normal offspring, while backcrosses (TrJ/ + X + / +) produce only mildly affected and normal offspring. We used the closely linked marker vestigial tail, vt, to test whether severely affected offspring of intercrosses (TrJvt/ + + X TrJvt/ + +) were TrJ/TrJ. In 5/6 intercrosses all severely affected animals were short-tailed and vice versa, while all mildly affected animals had long tails and vice versa. It is highly probable that the severely affected, mildly affected, and normal classes of intercross offspring were of TrJ/TrJ, TrJ/+, and +/+ genotypes, respectively.     

Bacillus cereus phage typing as an epidemiological tool in outbreaks of food poisoning.

Bacillus cereus is responsible for an increasing number of food poisoning cases. By using 12 bacteriophages isolated from sewage, a typing scheme for B. cereus isolates from outbreaks or sporadic cases of food poisoning was developed. The phages belonged to three morphotypes. Ten phages with contractile tails and icosahedral heads were members of the Myoviridae family, and two phages with noncontractile tails belonged to the Siphoviridae family. Phage 11 represented a new species. It had an isometric head and a very long contractile tail with long wavy tail fibers and was one of the largest viruses known. The vast majority of 166 B. cereus strains (161, or 97%) isolated from food poisoning cases were typeable. Of 146 strains isolated from 18 outbreaks, 142 (97%) could be divided into 17 phage types. A good correlation, on the order of 80 to 100%, between phage types of strains isolated from suspected foods and those of strains isolated from stools of symptomatic patients was observed. Most Bacillus thuringiensis strains were also typeable, providing further evidence of the close relatedness of B. cereus and B. thuringiensis. This phage typing scheme can be a valuable epidemiological tool in tracing the origins of food poisoning caused by B. cereus.     

Intra-articular osteochondroma of the knee joint in a patient with hereditary multiple osteochondromatosis

Hereditary multiple osteochondromatosis (HMO) is characterized by multiple osteochondroma (OC) arising from enchondrally formed bones. Such lesions are seen most commonly in the forearm, knee and hip joint. In long bones, OC arises adjacent to the physis and tends to remain in the metaphyseal legion. Therefore, it is rare that OC is located intra-articular of the joint and only few cases of intra-articular OC have been previously reported. Intra-articular OC could appear as a single loose body in a joint cavity. Thus, other joint disorders, such as osteochondritis dissecans should be ruled out in such cases. We herein report a case with an intra-articular OC in a knee joint cavity in the patient with HMO.     

Systematic isolation of transducing phages for Myxococcus xanthus.

Six new phages active on Myxococcus xanthus have been isolated from cultures of myxobacteria. The six are all capable of transduction, and they fall into three groups. Members of one group have long contractile tails, have a characteristic neutralization antigen, and resemble the previously described M×4. Members of a second group, exemplified by M×8, have very short tails and a characteristic antigen. M×9, the sole member of the third group, has a very short tail and a characteristic antigen. Phage M×8, which is active on fruiting as well as nonfruiting strains of M. xanthus, can transduce auxotrophic, antibiotic resistance and motility markers in M. xanthus. Although crude lysates of M×8 contain 58-nm diameter particles with a tail and 29-nm particles without tail, only 58-nm particles can form plaques and transduce. The plaque-forming particles of M×8 possess a single DNA molecule of 56,000 base pairs with a buoyant density of 1.726 g/cm³, virtually identical to that of the DNA from its host.     

Purification and analysis of a Gross murine oncornavirus protein with a molecular weight of about 12,000 specific for the Gross virus subgroup.

Two proteins of the tail of bacteriophage λ were purified in an active form and characterized for the study of phage assembly. The terminator protein (product of gene U), which stops the polymerization of the major tail protein at the correct tail length, was purified from crude lysates. It exists as a globular monomer of 16,000 daltons in the absence of magnesium ions and as a ring-like hexamer in the presence of 20 mM MgSO₄. It is a very acidic protein poor in lysine and lacking cysteine residues. Its secondary structure is rich in β-sheet and relatively poor in α-helix. Experiments using its antibody show that it is located at the proximal end of the tail. The major tail protein (product of gene V) was purified from dissociated tails or phage ghosts. This preparation was indistinguishable from the unassembled major tail protein in tail-defective lysates with respect to various properties except that the in vitro complementation activity was significantly lower. The gene V product consists of a polypeptide chain of about 25,000 daltons, which is rich in valine and threonine and which has no cysteine and no or an extremely small amount of histidine. Its secondary structure contains a large amount of random-coil, a relatively small amount of β-sheet, and very small amounts of α-helix. In solution it exists in a monomer-dimer equilibrium, and polymerizes only in the presence of the initiator for its assembly. The antibody against the major tail protein attaches all over the tubular part but not to the basal part of the tail.     

Persistent hypoglossal artery arising from the external carotid artery diagnosed by MR angiography

Purpose  

Extremely rarely, a persistent hypoglossal artery arises from the external carotid artery; only three cases have been reported in the English-language literature. The purpose of this paper is to report a case of this variation diagnosed by magnetic resonance (MR) angiography.     

RINGO/cdk1 and CPEB mediate poly(A) tail stabilization and translational regulation by ePAB

One activity that controls mRNA translation in vertebrate oocytes, embryos, and neurons is cytoplasmic polyadenylation. In Xenopus oocytes, where much of the biochemistry of this process has been elucidated, nuclear pre-mRNAs containing a cytoplasmic polyadenylation element (CPE) in their 3' untranslated regions (UTRs) have long poly(A) tails; once the RNAs are spliced and transported to the cytoplasm, the tails are shortened. Following the resumption of meiosis, the poly(A) tails are lengthened and translation ensues. CPEB is a sequence-specific RNA-binding protein that coordinates these events and does so by binding to the CPE as well as several factors including Gld2, a poly(A) polymerase, and PARN [poly(A)-specific ribonuclease], a deadenylase. Here, we show that ePAB, embryonic poly(A)-binding protein, transiently associates with the polyadenylation complex; it initially interacts with CPEB, but after polyadenylation, it binds the poly(A) tail. ePAB dissociation from CPEB is regulated by RINGO (Rapid Inducer of G(2)/M progression in Oocytes), a cyclin B1-like cofactor that activates cdk1, a protein kinase that phosphorylates CPEB. Subsequent ePAB binding to the poly(A) tail is necessary to protect the homopolymer from degradation by deadenylating enzymes. Poly(A)-bound ePAB also interacts with eIF4G, which instigates translation initiation of CPEB-bound mRNAs.     

Morphogenetic structures present in lysates of amber mutants of bacteriophage Mu

The Mu phage particle is structurally similar to that of the T-even phages, consisting of an icosahedral head and contractile tail. This study continues an analysis of the morphogenesis of the Mu phage particle by defining the structural defects resulting from mutations in specific Mu genes. Defective lysates produced by induction of 55 amber mutants, representing 24 essential genes, were examined in the electron microscope and categorized into eight classes based on the observed phage-related structures. (1) Mutations in genes lys, F and G, and some H mutations, did not cause a visible alteration in particle structure. (2) Mutants defective in genes A, B, and C produced no detectable phage structures, consistent with their lack of production of late RNA. (3) Extracts defective in genes L, M, Y, N, P, Q, V, W, and R contained only head structures, and these appeared normal. (4) K-defective mutants accumulated free heads as well as free tails which were longer than normal and variable in length. (5) Tails which appeared normal were the only structures found in T- and some I-defective extracts. (6) Free tails and empty heads accumulated in D-, E-, and some I- and H-defective extracts. These heads were as much as 16% smaller than normal heads. The heads found in some I amber lysates had a protruding neck-like structure and unusually thick shells suggestive of a scaffolding-like structure. (7) Defects in gene J resulted in the accumulation of unattached tails and full heads. (8) Previous analysis of lysates produced by inversion-defective gin mutants fixed in the G(+) orientation demonstrated that S and U mutants produced particles lacking tail fibers (F.J. Grundy and M.M. Howe (1984), Virology 134, 296-317). In these experiments with Gin+ phages S and U mutants produced apparently normal phage particles. Presumably the tail fiber defects were masked by the production of S' and U' proteins by G(-) phages in the population.     

Adenoid basal carcinoma of the cervix uteri

This paper describes a case of adenoid basal carcinoma of the uterine cervix, occurring in a woman aged 78 years. In view of the rarity and the limited knowledge of this group of neoplasms, details of the clinical history, the histological appearances, and the histochemical reactions are presented. An attempt is made to define the histogenesis of the tumour and some points on nonmenclature are discussed. It is suggested that the tumour arises from multipotential cervical basal cells and that the adenoid structures rather than being true glands are formed by degeneration of the connective tissue stroma. On the basis of a review of reported cases it seems possible that this tumour will be shown to be one of low-grade malignancy.     

The effects of changes in the environmental temperature on the growth of tail bones in the mouse

The tails of baby mice grow rapidly and independently of environmental temperature because they are kept warm by their mothers. After weaning, at approximately 3 weeks of age, tail growth is strictly related to environmental temperatures. During the first 2 weeks after weaning growth rates of 1.2-1.4 mm/day/tail were seen at 33 degrees and a maximum of 2.43 mm/day/tail was observed in one group kept at 36 degrees. Animals kept at 8 degrees or 4 degrees showed tail growth rates of 0.4 mm/day or less. However, the tails of animals transferred from either hot to cold or cold to hot during their first 2 weeks after weaning immediately grew at the same rate as those of animals kept in these conditions continuously, thus indicating that heat was acting directly on bone growth. The tails of animals kept continuously in the hot environment at 33 degrees completed their growth early so that their growth rate fell below that of controls after about 3 weeks of treatment (when they were 6-7 weeks old) and below that of "cold" animals after about 4 weeks (7-8 weeks old). The tails of the "control" and "cold" animals grew slowly for a very long time, 150-195 days. Even so, because of the very rapid early growth of tails in the hot environment, their final length was always greater than either the "control" or "cold" tails.     

The effects of changes in the environmental temperature on the growth of tail bones in the mouse.

The tails of baby mice grow rapidly and independently of environmental temperature because they are kept warm by their mothers. After weaning, at approximately 3 weeks of age, tail growth is strictly related to environmental temperatures. During the first 2 weeks after weaning growth rates of 1.2-1.4 mm/day/tail were seen at 33 degrees and a maximum of 2.43 mm/day/tail was observed in one group kept at 36 degrees. Animals kept at 8 degrees or 4 degrees showed tail growth rates of 0.4 mm/day or less. However, the tails of animals transferred from either hot to cold or cold to hot during their first 2 weeks after weaning immediately grew at the same rate as those of animals kept in these conditions continuously, thus indicating that heat was acting directly on bone growth. The tails of animals kept continuously in the hot environment at 33 degrees completed their growth early so that their growth rate fell below that of controls after about 3 weeks of treatment (when they were 6-7 weeks old) and below that of "cold" animals after about 4 weeks (7-8 weeks old). The tails of the "control" and "cold" animals grew slowly for a very long time, 150-195 days. Even so, because of the very rapid early growth of tails in the hot environment, their final length was always greater than either the "control" or "cold" tails.     

Directional actin polymerization associated with spotted fever group Rickettsia infection of Vero cells.

Members of the spotted fever group (SFG) of rickettsiae spread rapidly from cell to cell by an unknown mechanism(s). Staining of Rickettsia rickettsii-infected Vero cells with rhodamine phalloidin demonstrated unique actin filaments associated with one pole of intracellular rickettsiae. F-actin tails greater than 70 microns in length were seen extending from rickettsiae. Treatment of infected cells with chloramphenicol eliminated rickettsia-associated F-actin tails, suggesting that de novo protein synthesis of one or more rickettsial proteins is required for tail formation. Rickettsiae were coated with F-actin as early as 15 min postinfection, and tail formation was detected by 30 min. A survey of virulent and avirulent species within the SFG rickettsiae demonstrated that all formed actin tails. Typhus group rickettsiae, which do not spread directly from cell to cell, lacked F-actin tails entirely or exhibited only very short tails. Transmission electron microscopy demonstrated fibrillar material in close association with R. rickettsii but not Rickettsia prowazekii. Biochemical evidence that actin polymerization plays a role in movement was provided by showing that transit of R. rickettsii from infected cells into the cell culture medium was inhibited by treatment of host cells with cytochalasin D. These data suggest that the cell-to-cell transmission of SFG rickettsiae may be aided by induction of actin polymerization in a fashion similar to that described for Shigella flexneri and Listeria monocytogenes.     

Ultrastructure of Rickettsia rickettsii actin tails and localization of cytoskeletal proteins

Actin-based motility (ABM) is a mechanism for intercellular spread that is utilized by vaccinia virus and the invasive bacteria within the genera Rickettsia, Listeria, and Shigella. Within the Rickettsia, ABM is confined to members of the spotted fever group (SFG), such as Rickettsia rickettsii, the agent of Rocky Mountain spotted fever. Infection by each agent induces the polymerization of host cell actin to form the typical F (filamentous)-actin comet tail. Assembly of the actin tail propels the pathogen through the host cytosol and into cell membrane protrusions that can be engulfed by neighboring cells, initiating a new infectious cycle. Little is known about the structure and morphogenesis of the Rickettsia rickettsii actin tail relative to Shigella and Listeria actin tails. In this study we examined the ultrastructure of the rickettsial actin tail by confocal, scanning electron, and transmission electron microscopy. Confocal microscopy of rhodamine phalloidin-stained infected Vero cells revealed the typhus group rickettsiae, Rickettsia prowazekii and Rickettsia typhi, to have no actin tails and short (approximately 1- to 3-micrometer) straight or hooked actin tails, respectively. The SFG rickettsia, R. rickettsii, displayed long actin tails (>10 micrometer) that were frequently comprised of multiple, distinct actin bundles, wrapping around each other in a helical fashion. Transmission electron microscopy, in conjunction with myosin S1 subfragment decoration, revealed that the individual actin filaments of R. rickettsii tails are >1 micrometer long, arranged roughly parallel to one another, and oriented with the fast-growing barbed end towards the rickettsial pole. Scanning electron microscopy of intracellular rickettsiae demonstrated R. rickettsii to have polar associations of cytoskeletal material and R. prowazekii to be devoid of cytoskeletal interactions. By indirect immunofluorescence, both R. rickettsii and Listeria monocytogenes actin tails were shown to contain the cytoskeletal proteins vasodilator-stimulated phosphoprotein profilin, vinculin, and filamin. However, rickettsial tails lacked ezrin, paxillin, and tropomyosin, proteins that were associated with actin tails of cytosolic or protrusion-bound Listeria. The unique ultrastructural and compositional characteristics of the R. rickettsii actin tail suggest that rickettsial ABM is mechanistically different from previously described microbial ABM systems.